This invention relates to a copyholder with an indicator designed for movement relative to the copy area, an electrical drive and several actuating means for effecting the said relative movement.
Copyholders designed to accept copy, such as a manuscript, are known in which the relative displacement between indicator and copy is effected by means of an electric motor drive. Provided for actuation of the motor is an actuating means locally remote from the copyholder which is commonly designed as a manual or pedal switch (e.g. British Patent No. 859.135, Austrian Patent No. 220.171). Pressure exercised on the switch of the known apparatus moves the indicator until it has reached the target line. Subsequently pressure on the switch is discontinued for processing, such as for copying the line indicated. It will be appreciated that such copyholders involve disadvantages for the person who processes the copy. The continual shifting of the eyes from the machine operated to the copyholder interrupts the progress of writing, demands a high degree of concentration and is therefore not rational. Narrow-spaced manuscripts of some length may therefore result in fatigue symptoms so that actuation of the switch is no longer properly assessed and lines are e.g. skipped. Such apparatus are also used to train for high reading rates.
Further copyholders are known in which advance is effected not electrically but by the effect of gravity or by a string line (e.g. German Patent No. 827.955) and in which the indicator advances only one step upon actuation. Apart from the uncertain drive, such apparatus involve considerable disadvantages in practice because adjustment of the advance interval is commonly complicated. These known apparatus disadvantageously also do not permit continuous advance of the indicator which is desired for reading material with varying successive sections.
While eliminating the above disadvantages, the invention has for its object to provide a copyholder with which line advance can be actuated with minimum distraction from the machine operated, by way of example a typewriter, while at the same time ensuring that no lines of the copy are skipped. The advance interval and stroke respectively must be capable of being discretionally selected in order to enable the indicator to be effortlessly adjusted for any line spacing. In addition, it is to be ensured that intervals frequently employed, by way of example millimeter intervals or standardized typewriter line spaces, can be preselected and reproduced. Moreover, it must be possible, if desired, to move the indicator continuously from the end of one paragraph to the beginning of the one next following.
Accordingly the invention relates to a copyholder with a copy located thereon, an indicator arranged for movement relative to the copy surface, electrical driving means and several actuating means, characterized
- by a control unit connected to the driving means which sets the driving means in motion on receipt of a starting signal from a first actuating means, PA0 - by a stopping device connected to the control unit for the automatic issuance of a stopping order to the control unit for stopping the driving means and a design of the driving means and the stopping means of the type that enables relative movements of discretional predetermined length to be effected, PA0 - and by a second actuating means connected to the control unit for the selective issuance of starting orders and stopping orders independent of the stopping device.